1. Field of the Invention
The present invention relates generally to a gas heater utilizing catalyst reaction of a combustion gas, and particularly concerns a portable gas heater which can be started safely and easily by a simple operation for moderate warming of a heating plate for holding a heating object, such as a mat soaked with an insecticide.
2. Description of the Prior Art
In recent years, trials are made to react butane or the like combustion gas with metal catalyst such as platinum or the like for applying resultant heat in heating portable hair curler, portable insence radiator, portable insecticide radiator, etc. The above-mentioned portable apparatuses utilizing the catalyst reaction of the combustion gas are paid attention since wide utilizations and development are expected owing to their features that no electric power is used.
On the other hand, from many years ago, insecticide-mat-heating apparatus for evaporating insecticide soaked in a mat by heating a filament heater or a semiconductor heater by use of commercial electric power source. However, such conventional electric mat heater requires a considerably large electric power to raise the heating plate to a certain temperature enough to evaporate the insecticide, such as 150.degree. C. Accordingly, due to shortage of necessary power to raise the temperature, the insecticide mat heating apparatus has not been able to be electrified.
Besides, a catalyst heater apparatus was recently trial-manufactured. This is configurated to use a dry cell as its starting means, wherein an electric filament is red-heated to ignite combustion gas. Such trial-manufactured apparatus has problems of dry cell replacement, taking some time to ignite the combustion gas by red-heating the filament and insufficient reliability of starting. Furthermore, since an initial ignition of the combustion gas is carried out in a burning chamber which is originally designed for the catalyst-reaction, condition for igniting is dissatisfactory because of excessive contents of the combustion gas, shortage of air, etc. Therefore, such apparatus has, on top of the unreliability of the ignition, a liability of making big explosion sound at the time of ignition. Such sound is not only uncomfortable for the user, but also is undesirable for safety and service life time of the apparatus.